Method and device for unlocking a hatch of an aircraft landing gear

Abstract

Method for unlocking a hatch of an aircraft landing gear mounted to move between an open position and a closed position, the hatch being associated with latching means comprising a first latching box and a second latching box arranged to individually block the hatch in the closed position, a first unlocking actuator and a second unlocking actuator arranged to act respectively on the first latching box and the second latching box in order to deactivate them, and means for detecting the hatch in the closed position, the method comprising the step of sequentially deactivating the latching boxes to detect a failure of the last latching box to have been deactivated. Device and aircraft implementing this method. FIGURE OF THE ABSTRACT: Fig.3A

Description

Title of the invention: Method and device for unlocking a hatch of an aircraft landing gear

[0001] The present invention relates to the locking and unlocking of a hatch, in particular an aircraft landing gear hatch.

[0002] BACKGROUND OF THE INVENTION

[0003] Aircraft are known which are equipped with retractable landing gear, with bays intended to receive these landing gear when the aircraft is in flight, and with hatches for closing these bays. The deployment and retraction of the landing gear, as well as the opening and closing of the hatches, are carried out using maneuvering actuators such as jacks.

[0004] When the landing gear reaches the retracted position, it is automatically held in this position by retaining means. Similarly, when the hatch reaches the closed position, it is automatically locked in this position by hooking means which generally comprise a single hooking housing on which a hook is articulated for trapping a roller fixed to the hatch. The hook is released using a main unlocking actuator, most often hydromechanical or electromechanical. The hooking means often comprise an emergency actuator capable of unlocking the hook if the main actuator is inoperative.

[0005] In flight, the unhooking of the hook and the opening and closing of the hatch are controlled during deployment and retraction sequences of the landing gear. It should be noted that the hatch is closed and hooked when the landing gear is retracted but also once it has been deployed.

[0006] This type of architecture makes it possible to prevent any untimely deployment of the lander in the event of failure of its retaining means, provided that the hatch and its attachment means are sized to ensure that the lander is held in place under this type of load.

[0007] According to regulation CS-25 ("Certification Specifications for Large Aeroplanes"), it is necessary to classify the single attachment box equipping the hatch as a principal structural element ("Principal Structural Element" or PSE) in order to ensure that no single failure of the attachment box can result in an event tending to damage the overall structural integrity of the aircraft.

[0008] However, such a classification has consequences on the design of the attachment box, its manufacturing process, the nature of the materials it is made of, but also its integration into the aircraft so that it can be visually inspected in order to detect possible anomalies such as cracks.

[0009] SUBJECT OF THE INVENTION

[0010] The aim of the invention is to propose a solution which at least partially overcomes the aforementioned drawbacks. Summary of the invention

[0011] To this end, a method is proposed for unlocking a hatch of an aircraft landing gear mounted to move between an open position and a closed position, the hatch being associated with attachment means comprising a first attachment housing and a second attachment housing arranged to individually block the hatch in the closed position, a first unlocking actuator and a second unlocking actuator arranged to act respectively on the first attachment housing and the second attachment housing in order to deactivate them, and means for detecting the hatch in the closed position.

[0012] According to the invention, the method comprises, during a first sequence of opening the hatch locked in the closed position by the first latching box and the second latching box, the following steps:

[0013] - control the first unlocking actuator to deactivate the first hanging box;

[0014] - wait for a first waiting time longer than the time required for the trapdoor to initiate its transition from the closed position to the open position so as to allow the detection means to detect a possible start of opening of the hatch;

[0015] - detect the possible start of opening of the hatch by the detection means and in deduce, where appropriate, a failure of the second attachment box;

[0016] - control the second unlocking actuator to deactivate the second hanging box.

[0017] It is understood that the offset actuation of the hooking boxes makes it possible to test that the last-actuated hooking box is fulfilling its function at least for the duration of the waiting time. This hooking box is then considered to be functional.

[0018] Advantageously, the method comprises, during a second sequence of opening the hatch locked in the closed position by the first latching box and the second latching box, the following steps:

[0019] - control the second unlocking actuator to deactivate the second hanging box;

[0020] - wait a second waiting time longer than the time required for the trapdoor to initiate its passage from the closed position to the open position so as to allow the detection means to detect a possible start of opening of the trapdoor;

[0021] - detect the possible start of opening of the hatch by the detection means and in deduce, where appropriate, a failure of the first attachment box; and

[0022] - control the first unlocking actuator to deactivate the first hanging box.

[0023] According to a particular characteristic, the first sequence of opening the hatch corresponds to a retraction of the landing gear after takeoff, and the second sequence of opening the hatch corresponds to a deployment of the landing gear before landing.

[0024] According to another particular characteristic, the first sequence and the second sequence of opening the hatch are carried out on the ground.

[0025] In particular, the method further comprises the step of recording, in a maintenance memory of the aircraft, the failure of the first attachment box and / or of the second attachment box, and of informing the pilot of the aircraft thereof.

[0026] In particular, the first instant and the second waiting time are identical and substantially equal to 0.5 seconds.

[0027] The invention also relates to a device for unlocking a hatch of an aircraft landing gear. The device comprises latching means comprising a first latching housing and a second latching housing arranged to lock the hatch in the closed position, a first unlocking actuator and a second unlocking actuator arranged to act respectively on the first latching housing and the second latching housing in order to deactivate them, means for detecting the hatch in the closed position, and a control unit arranged to implement such a method.

[0028] In particular, the detection means comprise at least one proximity sensor.

[0029] The invention also relates to an aircraft provided with such a device. Brief description of the drawings

[0030] The invention will be better understood in light of the following description, which is purely illustrative and non-limiting, and must be read in conjunction with the appended figures, among which:

[0031] [Fig-1] [Fig.l] is a schematic view of a locking device, according to a particular embodiment of the invention, of a hatch of an aircraft landing gear;

[0032] [Fig.2] [Fig.2] illustrates a method of unlocking the hatch illustrated in [Fig.l], during a lander retraction sequence;

[0033] [Fig.3A] [Fig.3A] illustrates a method of unlocking the hatch illustrated in [Fig.l], during a lander deployment sequence;

[0034] [Fig.3B] [Fig.3B] illustrates a method of unlocking the hatch illustrated in [Fig.l], during a retraction sequence of the lander; DETAILED DESCRIPTION OF THE INVENTION

[0035] As illustrated in [Fig.l], the invention is described here in relation to an aircraft 1 comprising a landing gear 10 articulated on a structure 2 of the aircraft 1 between a deployed position illustrated here and a retracted position in which the landing gear 10 is received in a hold 3 closable by a hatch 20.

[0036] With reference to [Fig. 2], a double-acting cylinder 11 is coupled to the landing gear 10 and allows it to be maneuvered between the retracted position and the deployed position. The landing gear 10 is held in the retracted position by a single hooking housing 13 provided with a hook allowing an olive secured to the landing gear 10 to be hooked when the latter reaches the retracted position. The unhooking of the hook is controlled by a hydromechanical unlocking actuator 12.

[0037] Similarly, a double-acting cylinder 21 is coupled to the hatch 20 and allows it to be maneuvered between an open position allowing the deployment and retraction of the landing gear, and a closed position closing the hold 3. The hatch 20 is held in the closed position by a first attachment box 23.1 and a second attachment box 23.2, both secured to the structure of the aircraft 1. The first attachment box 23.1 is provided with a hook 24.1 allowing a first olive 25.1 secured to the hatch 20 to be hooked when said hatch 20 arrives in the closed position. The second attachment box 23.2 is provided with a hook 24.2 allowing a second olive 25.2 secured to the hatch 20 to be hooked when said hatch 20 arrives in the closed position. It will be understood that the first attachment box 23.1 makes it possible to maintain the hatch 20 in the closed position independently of the second attachment box 23.2, and vice versa.The first hanging box 23.1 and the second hanging box 23.2 are identical here, as are the first olive 25.1 and the second olive 25.2.

[0038] The unhooking of the hook 24.1 equipping the first attachment housing 23.1 is controlled by a first hydromechanical unlocking actuator 22.1. Similarly, the unhooking of the hook 24.2 equipping the second attachment housing 23.2 is controlled by a second hydromechanical unlocking actuator 22.2. The first and second unlocking actuators 22.1, 22.2 are identical here.

[0039] The cylinder 11 used to maneuver the landing gear 10 is controlled by a monostable distributor DU connected to a source of pressurized fluid P. The actuator 12 making it possible to deactivate the attachment box 13 is controlled by a monostable valve V12 connected to the source of pressurized fluid P.

[0040] The cylinder 21 used to operate the hatch 20 is controlled by a monostable distributor D21 connected to the source of pressurized fluid P. The first actuator 22.1 for deactivating the first attachment box 23.1 is controlled by a first monostable valve V22.1 connected to the source of pressurized fluid P. Similarly, the second actuator 22.2 for deactivating the second attachment box 23.2 is controlled by a second monostable valve V22.2 connected to the source of pressurized fluid P.

[0041] A monostable isolation valve Vi makes it possible to isolate, in particular during certain flight phases, the distributors DU, D21 and the control valves V12, V22.1, V22.2 from the source of pressurized fluid P, in order to limit the untimely deployment and retraction of the landing gear 10, but also the untimely opening and closing of the hatch 20.

[0042] It will be noted that, in the event of failure of the attachment box 13, the landing gear 10 would nevertheless be retained in the hold 3 by the hatch 20 locked in the closed position via the first attachment box 23.1 and the second attachment box, such that the locking of the hatch 20 tends to limit any untimely deployment of the landing gear 10.

[0043] The aircraft 1 also comprises a control unit U arranged to control the distributors D21, D22 connected to the cylinders 11, 21 and the valves V12, V22.1, V22.2 connected to the actuators 12, 22.1, 22.2, so as to control the deployment and retraction of the landing gear 10, the locking of said landing gear 10 in the retracted position, the opening and closing of the hatch 20, and the locking of the hatch in the closed position.

[0044] The aircraft 1 further comprises a proximity sensor 40 of the inductive type connected to the control unit U and arranged to detect the presence of the hatch 20 in the closed position, and therefore capable of revealing a start of opening of said hatch 20 up to a state of non-closure of the hatch 20.

[0045] In order to check the integrity of the first attachment box 23.1 and the second attachment box 23.2, and thus protect against a latent failure of these, the control unit U is arranged to implement a method for unlocking the hatch 20 of the landing gear 10.

[0046] According to the invention, the method comprises, during a retraction sequence of the landing gear 10 after takeoff, the following steps ([Fig.3A]):

[0047] - control the cylinder 21 via the distributor D21 to open the hatch 20 (step 100); - control the first unlocking actuator 22.1 via the valve V22.1 to deactivate the first latching box 23.1 (step 110); - wait for an initial waiting time Tl greater than the time required for the hatch 20 to initiate its passage from the closed position to the open position so as to allow the proximity sensor 40 to detect a possible start of opening of the hatch 20 (step 120); - detect the possible start of opening of the hatch 20 by the proximity sensor 40 (step 130) and deduce therefrom, if applicable, a failure of the second attachment box 23.2 which will be recorded in a maintenance memory of the aircraft 1 and reported to the pilot of the aircraft 1 (step 140); - control the second unlocking actuator 22.2 via valve V22.2 to deactivate the second latching box 23.2 (step 150); - when the hatch 20 reaches the open position, control the actuator 12 for unlocking the landing gear 10 via the valve V12 and control the cylinder 11 to retract said landing gear 10; - when the landing gear 10 reaches the retracted position, control the cylinder 21 via the distributor D21 to close the hatch 20 (step 160); and - when the hatch reaches the closed position, cut off the power supply to the cylinders 11, 21 and the unlocking actuators 12, 22.1, 22.2 via the isolation valve Vi (step 170).

[0048] The method also comprises, during a deployment sequence of the lander 10 before landing, the following steps ([Fig.3B]):

[0049] - control the cylinder 21 via the distributor D21 to open the hatch 20 (step 200); - control the second unlocking actuator 22.2 via valve V22.2 to deactivate the second latching box 23.2 (step 210); - wait for a second waiting time T2 greater than the time required for the hatch 20 to initiate its passage from the closed position to the open position so as to allow the proximity sensor 40 to detect a possible start of opening of the hatch 20 (step 230); - detect the possible start of opening of the hatch 20 by the proximity sensor 40 and deduce therefrom, if necessary, a failure of the first attachment box 23.1 which will be recorded in the maintenance memory and reported to the pilot of the aircraft 1 (step 240); - control the first unlocking actuator 22.1 via the valve V22.1 to deactivate the first latching box 23.1 (step 250); - when the hatch 20 reaches the open position, control the cylinder 11 to deploy the landing gear 10; - when the landing gear 10 arrives in the deployed position, control the cylinder 21 via the distributor D21 to close the hatch 20 (step 260); and - when the hatch reaches the closed position, cut off the power to the cylinders 11, 21 and actuators 12, 22.1, 22.1 for unlocking via the isolation valve Vi (step 270).

[0050] The first waiting time T1 and the second waiting time T2 are here identical and substantially equal to 0.5 seconds.

[0051] It will be understood that such a method makes it possible to alternately test the correct operation of the first unlocking box 23.1 and the second unlocking box 23.2 on each complete flight cycle of the aircraft 1.

[0052] The proper functioning of the first unlocking box 23.1 and the second unlocking box 23.2 can also be tested on the ground, in particular when the aircraft 1 is parked. The method then comprises the following steps:

[0053] • during a first sequence of opening the hatch 20:

[0054] - control the cylinder 21 via the distributor D21 to open the hatch 20; - control the first unlocking actuator 22.1 via valve V22.1 to deactivate the first latching box 23.1; - wait for the waiting time Tl so as to allow the proximity sensor 40 to detect a possible start of opening of the hatch 20; - detect the possible start of opening of the hatch 20 by the proximity sensor 40 and deduce therefrom, if necessary, a failure of the second attachment box 23.2 which will be recorded in the maintenance memory and reported to the pilot of the aircraft 1; - control the second unlocking actuator 22.2 via valve V22.2 to deactivate the second latching box 23.2; - when the hatch 20 reaches the open position, control the cylinder 21 via the distributor D21 to close the hatch 20;

[0055] • during a second sequence of opening the hatch 20:

[0056] - control the cylinder 21 via the distributor D21 to open the hatch 20; - control the second unlocking actuator 22.2 via valve V22.2 to deactivate the second latching box 23.2; - wait for the waiting time T2 so as to allow the proximity sensor 40 to detect a possible start of opening of the hatch 20; - detect the possible start of opening of the hatch 20 by the proximity sensor 40 and deduce therefrom, if necessary, a failure of the first attachment box 23.1 which will be recorded in the maintenance memory and reported to the pilot; - control the first unlocking actuator 22.1 via valve V22.1 to deactivate the first latching box 23.1; - when hatch 20 reaches the open position, control cylinder 21 via distributor D21 to close hatch 20.

[0057] The verification of the correct operation of the first unlocking box 23.1 and the second unlocking box 23.2 can also be carried out on the ground by an operator manually and alternately deactivating the first and second hooking boxes 23.1, 23.2 to release the hatch 20.

[0058] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0059] Although here the first and second attachment boxes 23.1, 23.2 are identical, they may be different.

[0060] Although here the first and second unlocking actuators 22.1, 22.2 are hydromechanical, they can be of a different nature (electromechanical, etc.).

[0061] Although here the waiting times T1 and T2 are identical, they can be different: the waiting time T1 can be greater than the waiting time T2, or vice versa.

[0062] Although here the detection of the hatch 20 in the closed position is ensured by a proximity sensor 40, other detection means can be envisaged (contact sensor, etc.).

Claims

Claims

1. Method for unlocking a hatch (20) of a landing gear (10) of an aircraft (1) mounted to move between an open position and a closed position, the hatch being associated with hooking means comprising a first hooking box (23.1) and a second hooking box (23.2) arranged to individually block the hatch in the closed position, a first unlocking actuator (22.1) and a second unlocking actuator (22.2) arranged to act respectively on the first hooking box and the second hooking box in order to deactivate them, and means (40) for detecting the hatch in the closed position, the method comprising, during a first sequence of opening the hatch (20) blocked in the closed position by the first hooking box (23.1) and the second hooking box (23.2), the following steps: - controlling the first unlocking actuator (22.1) to deactivate the first latching box (23.1); - wait for a first waiting time (Tl) greater than the time required for the hatch to initiate its passage from the closed position to the open position so as to allow the detection means (40) to detect a possible start of opening of the hatch; - detect the possible start of opening of the hatch by the detection means (40) and deduce therefrom, if applicable, a failure of the second latching box (23.2); and - control the second unlocking actuator (22.2) to deactivate the second latching box (23.2).

2. Method according to claim 1, comprising, during a second sequence of opening the hatch (20) locked in the closed position by the first latching box (23.1) and the second latching box (23.2), the following steps: - controlling the second unlocking actuator (22.2) to deactivate the second latching box (23.2); - waiting for a second waiting time (T2) greater than the time necessary for the hatch to initiate its passage from the closed position to the open position so as to allow the detection means (40) for detecting a possible start of opening of the hatch; - detecting the possible start of opening of the hatch by the detection means (40) and deducing therefrom, if necessary, a failure of the first latching box (23.1); and - controlling the first unlocking actuator (22.1) to deactivate the first latching box (23.1).

3. Method according to claim 2, in which the first sequence of opening the hatch (20) corresponds to a retraction of the landing gear (10) after a takeoff, and the second sequence of opening the hatch (20) corresponds to a deployment of the landing gear (10) before a landing.

4. Method according to claim 2, in which at least one of the first sequence and second sequence of opening the hatch (20) is carried out on the ground.

5. Method according to any one of claims 2 to 4, further comprising the step of recording, in a maintenance memory of the aircraft (1), the failure of the first attachment box (23.1) and / or of the second attachment box (23.2), and of informing the pilot of the aircraft thereof.

6. A method according to any one of claims 2 to 5, wherein the first waiting time (T1) and the second waiting time (T2) are identical and substantially equal to 0.5 seconds.

7. Device for unlocking a hatch (20) of a landing gear (10) of an aircraft (1), the device comprising hooking means comprising a first hooking box (23.1) and a second hooking box (23.2) arranged to block the hatch in the closed position, a first unlocking actuator (22.1) and a second unlocking actuator (22.2) arranged to act respectively on the first hooking box and the second hooking box in order to deactivate them, means (40) for detecting the hatch in the closed position, and a control unit (U) arranged to implement the unlocking method according to any one of the preceding claims.

8. Device according to claim 7, wherein the detection means comprise at least one proximity sensor (40).

9. Aircraft provided with a hold which is closed by a hatch and which receives a landing gear, an unlocking device according to claim 7 or 8 being associated with the hatch.

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